The objective of this project is to develop and field-test an electronic sensor system that will detect the voltage-intensity, and the distance of overhead high-voltage power lines from mobile cranes. The system will alarm the crane operator when the crane boom gets excessively close to a power line, and if the boom gets dangerously close, the system will trigger a loud alarm and a flashing light to warn the crane operator and those working in the vicinity of the crane. A number of sensors attached to the crane boom will be connected together by a powered sensor bus and then to a microprocessor located in the operator's cabin. A smaller system using similar design will also be developed for conductive scaffolds, aerial man-lifts, boom trucks, and other self-propelled machinery that make physical contact to a power line. The system will be field-tested on the Operating Engineers, Local #17, training grounds. Several crane manufacturers will later be approached for testing the system on construction work sites. In 1981, for which a complete data is available, there were approximately 2300 lost workday mobile crane injuries due to contact with power lines including 115 fatalities and 200 permanent total disabilities. Also, metal and conductive scaffolds killed 47 workers in similar accidents in 1991; and 7 workers are electrocuted every year in aerial lifts during tree trimming. The 1999 cost of these injuries estimates to $259 million. It is expected that at least 50% of the crane manufacturers and rental companies will install this system on their cranes, resulting in a saving of $130 million per year, besides saving 85 lives, 100 permanent total disabilities, and 993 severe injuries. Two companies, both located in Buffalo area, will work in consortium to develop the proposed system. The full objectives of the project will be accomplished in three years at a total direct cost of $494,647.